Reading through this GDD shows a promising premise for a Retrospective game. At first thought it made me think of a Point-and-Click adventure to the theme of European art with some real-world lore Assassin's Creed style.
The simplicity of navigating the game's levels and using more visual elements to piece together clues will be a welcome intellectual challenge for people with, or looking to sharpen their, observational and inferential skills. I had a few questions regarding the word bank and Ad-Lib puzzle system. Are you able to see the color-coding of words to blank spaces immediately or do you need to find another clue/solve another puzzle first to show their color association? Having or not having that aid in the game could change its difficulty.
Learning more about the details of the kinds of challenges you'd encounter in an exhibit would also be intriguing (finding discrepancies in paintings, symmetrizing/asymmetrizing art pieces, kinetic sculpture completion/repair puzzles, or creating visual balance within an exhibit room).
The game's narrative and characters are sure to be a treat for those intrigued in the kind of story the game presents. You and your team did well! I look forward to hearing more about how this project develops!